Sialyltransferase Activities in Two Neuronal Models : Retina and Cultures of Isolated Neurons
Gangliosides have been found in various organs and tissues, however they are localized in a rather high amount and with a great diversity in the central nervous system (see for review LEDEEN and YU, 1976). The synthesis of gangliosides occurs by different pathways, requiring glycosyltransferases and sialyltransferases. Activities of these enzymes were studied both in non-nervous and in nervous tissues, with respect to their subcellular localization and kinetic properties. It was postulated that sialic acid residues on cell surfaces are involved in membrane-related cellular phenomena such as cellular recognition and adhesion, malignant transformation, contact inhibition and cellular migration (see for review SCHAUER, 1973). Further sialosyl groups seem to be involved in the receptor function of gangliosides (YAMAKAWA and NAGAI, 1978). Moreover, it was hypothesized that the formation of an enzyme-substrate complex between a glycosyltransferase from one cell and one acceptor from another could be responsible for cellular recognition (ROSEMAN, 1970).
KeywordsNeuronal Model Exogenous Substrate Sialic Acid Residue Endogenous Activity Chick Retina
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- CUATRECASAS P. and ANFINSEN C.B. (1971): Affinity chromatography, in “Methods in Enzymology”, JACOBY W.B., Ed., Vol. 22, Academic Press (New York and London), pp. 345–378.Google Scholar
- DREYFUS H., HARTH S., PRETI A., URBAN P.F. and MANDEL P. (1978): Studies on retinal ganglioside metabolism, in “Enzymes of Lipid Metabolism”, GATT S., FREYSZ L. and MANDEL P., Eds., Advances in Experimental Biology, Vol. 101, Plenum Press (New York), pp. 655665.Google Scholar
- DREYFUS H., URBAN P.F., EDEL-HARTH S. and MANDEL P. (1975): metabolic approaches, in “Ganglioside Function”, PORCELLATI G., CECCARELLI B. and TETTAMANTI G., Eds., Advances in Experimental Biology, Vol. 71, Plenum Press (New York and London), pp. 163–188.Google Scholar
- HARTH S., DREYFUS H., URBAN P.F. and MANDEL P. (1978): Direct thin layer chromatography of gangliosides of a total lipid extract. Analyt. Biochem. 86, 543–551.Google Scholar
- LEDEEN R.W. and YU R.K. (1976): Gangliosides of the nervous system, in “Glycolipid Methodology”, WITTING L.A., Ed., American Oil Chemist’s Society ( Champaign, Illinois ), pp. 187–214.Google Scholar
- YAMAKAWA T. and NAGAI Y. (1978): Glycolipids at the cell surface and their biological functions. Trends Biochem. Sci. 3, 128–131.Google Scholar